Found this article interesting:
Can Blood Type Determine Your Personality? ~Natalie Josef
In Japan, blood type is used to determine one’s personality and temperament. Like astrology, the scientific community often dismisses blood type as an indicator of personality, but that doesn’t stop its popularity in Japanese women’s magazines, where blood type horoscopes are published. In Japanese video games, blood type is commonly a dimension in character creation. In fact, some Japanese might even be shocked if a foreigner didn’t know her blood type.
What Your Blood Type Says About Your Personality
You are the social butterflies. Often popular and self-confident, you are very creative and always seem to be the center of attention. You make a good impression on people and you’re often quite attractive. Organized and determined, your stubbornness will help you reach your goals. You make good leaders. Lovewise, O is most compatible with O and AB. Common career choices: banker, politician, gambler, minister, investment broker, and pro athlete.
Type As may seem calm on the outside, but inside, you’re filled with anxiety and worry. You’re perfectionists and often shy and sensitive. Usually introverted, you’re stable and thoughtful. You make good listeners and are sensitive to color and your surroundings. You like to be fashionable and are up on the latest trends, but never flashy or gaudy. You like romantic settings and often shun reality for fantasy worlds. A is most compatible with A and AB in the love department. Common career choices: accountant, librarian, economist, writer, computer programmer, and gossip columnist.
You can be very goal-oriented and often complete the ambitious tasks set before you. Outgoing and very charming, you’re good at reading people and providing support. Though critical of appearance (but not your own), you aren’t picky and are unlikely to dwell over the little things. Type Bs are impulsive individualists who often create their own path in life. You are very strong and optimistic. B is most compatible with B and AB lovers. Common career choices: cook, hairdresser, military leader, talk show host, and journalist.
Not surprisingly, ABs can be quite dualistic, possessing both A and B traits. You may be shy and outgoing, and hesitant and confident. You often stand out from others, don’t like labels, and are nice and easy going. You are logical and determined to do things correctly. Usually trustworthy, you like to help others. You often speak in a serious manner. Your patience, concentration, and intelligence are admirable. AB can find a soul mate with any other blood type. Common career choices: bartender, lawyer, teacher, sales representative, and social worker.
I personally don't buy into horoscopes. They can be tailored to fit anyone. I am type A and I can find my traits in all of these, not just A.